Cholera Toxins. Produced by Vibrio cholerae, cholera toxin (CT) is a multimeric enterotoxin that transfers ADP-ribose to a G protein, locking adenylate cyclase in an 'on' position.
echinoderm. n. 1. (Animals) any of the marine invertebrate animals constituting the phylum Echinodermata, characterized by tube feet, a calcite body-covering (test), and a five-part symmetrical body. The group includes the starfish, sea urchins, and sea cucumbers.ny of various invertebrate sea animals having a hard spiny outer covering, an internal skeleton, and a radially symmetrical body. Starfish, sea urchins, and sea cucumbers are echinoderms.
The adults are recognizable by their (usually five-point) radial symmetry, and include such well-known animals as starfish, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or stone lilies. Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone.The phylum contains about 7000 living species, making it the second-largest grouping of deuterostomes (a superphylum), after the chordates (which include the vertebrates, such as birds, fishes, mammals, and reptiles).ll echinoderms are marine and nearly all are benthic. The oldest known echinoderm fossil may be Arkarua from the Precambrian of Australia. It is a disc-like fossil with radial ridges on the rim and a five-pointed central depression marked with radial lines.